Molded socket



Nov. 10, A193,6. A. M. DRAVING MOLDED SOCKET l Original Filed Sept. 2, 1931 l- I P. ,s

Reissued Nov. 10, 1,936*- UNITED STATES MOLDED SOCKET Arthur M. Draving, Philadelphia, Pa.,

to Hugh H. Eby.

Original No. 1,956,316, d

assigner Philadelphia, Pa.

ated April 24, 1934, Serial No. 560,680, September 2, 1931-. Application for reissue April 18, 1936,

` 10 Claims.

My invention relates to improvements in electrical receptacles for vacuum tubes, electrical plugs, and the like.

Devices of this character with which I am familiar, have in the past had the following d efects; In the insertion of the prongs of vacuum tubes into their sockets, it has been found that the solder on the bottom of the prongs has traced lines o1 conducting material on the surface of the receptacle between the sockets or apertures in the receptacle. This has resulted in leakage paths between the terminals of the vacuum tube or other device, and it has been particularly objectionable in the case of recep'- tacles constructed of ceramic material having a roughened or porous surface. Additionally, dimculty has been encountered in socket contact terminalaof providing contact structure vadapted to make ilrm electrical contact along a plurality of points on the terminal prongs of the vacuum tube,l or other plug-in device.

Accordingly, an vobject of my invention is to providev an electrical receptacle so constructed as to prevent the formation of conducting or leak- 'age paths between terminals.

' A further object of my invention is to provide a receptacle of the "low-loss" type, preferably formed of molded ceramic material, having a minimum'of insulation material therein and a maximum of efiiciency when used in connection with radio apparatus employing short wavelengths. y

A still further object of my invention is to prov videvcontact terminal structure for the sockets,

having extreme .simplicity of design and an improved electrical contact'with the prongs of a plug-in device.

A still further object of my invention is to provide electrical contact structure-of novel design for my improved receptacle, together with novel means for securing the contact structure in assembled relation with the receptacle.

With'these and other objects in view which will appear from the following description, the invention comprises the methods and the devices described and set forth in the following specification and claims.

The various features of the invention are illustrated in the accompanying drawing in which:

Fig. 1 is a plan view of my improved socket receptacle embodying a preferred form of the invention, v

Fig. 2 is a longitudinal view in section of the socket receptaclev shown in Fig. 1 and taken on lines 2 2,

Serial No. 75.243

Fig. 3 is a bottom plan view of receptacle shown inFigs. 1 and 2,

Fig. 4 is a fragmentary view in sections slmiiar to Fig. 2 embodying a modified forni of my invention, and serving to illustrate one of the 5 principles of my invention,

Fig. 5 is alongitudinal view in section-of a modified form of my improved socket receptacle,

Fig. 6 is a perspective view of the novel contact element forming a part .oi' my improved 10 'socket receptacle,

Fig. 7 is a plan view partly in section of my imv proved resilient contact structure and serving to illustrate its operative relation to the prong terminal of a plug-in device, and l5 Fig. 8 is a fragmentary view in longitudinal section of one end of the receptacle of`Fig. 1, however, in slightly modied form.

Referring to the construction of my improved socket in Figs. l, 2 and 3, I have provided a 20 molded socket receptacle l, having sockets orv bores 3 in the topwall portion 5 for the insertion of the prongs of a plug-in device. The receptacle shown is composed oi' molded ceramic material or other desirable material having sat- 25 isfactory mechanical strength and desirable lowloss characteristics for radio frequency purposes. This receptacle comprises the top portion 5 and the lower sidewall rportion 1, these portions forming a hollow chamber 9. In the 30 device' whichlI have designed and built, I have employed the brackets or partitions II for strengthening purposes and valso for insulating reasons, located between the respective socket 'bores and contact structure, and connecting the 35 top and side wall portions.

The receptacle is adapted to be secured to the metal chassis of a radio set by means of holes I2, the raised bosses Mserving to space the top face of the receptacle from the chassis. Such 4 relation is illustrated clearly in connection with Fig. .8, hereinafter described.

, Coaxially disposed .with each of said sockets or bores is a counterbore or well I3 of enlarged diameter, formed in the sur-face of the top wail, and

.having preferably asharp corner at i5. I have shown a circular groove I1 on the surface of the `top wall in alignment with the socket bores 3 for the socket assisting-in the insertion of a plug-in device. As 50 socket between the socket bores, and particularly in the groove I1 when used, is .effectively broken by the presence of the corner I5. It may be considered that this corner I5 has aradius of j curvature which is less thanthat of the end oi theprong I3.

In the modified form-of Fig. 5, I have illustrated my invention in its application to a lami' nated socket of the type disclosed in Patent No.l

1,771,094 to McFadden. Here, the 4in the top plate23 is made larger aperture I3' in diameter Athan aperture- I3in the bottom plate 25, thereby `larly has an aperture 4I therein.

forming in effect a step with a corner, as in Fig. 2, and for a similar purpose. The guide disc 31 'is preferably -made sufficiently small in diameter that its perimeter is spaced from the prong terminals of the plug-in device when in the -operating position in thesocket. f

Referring to Fig. 6, I have illustrated, in perspective, a novel form of contact terminal structure used in the ,above forms of socket as shown in Figs. 1 to 5. This contact structure is formed from a strip 23 of any desirable resilient vmatc-l v rial such as phosphor-bronze, and has a portion 3| bent at right angles thereto. This portion has a pair of arms orfngers 33 extending therefrom with inwardly directed ends 34 adapted to grip the sides of a terminal prong.

`The right-angled portiony 3l has its end portion 35 preferably bent backwardly and provided with an aperture 31. The base portion 23 simi- A slot 33 is disposed longitudinally of the right angled portionjl, and connects the apertures 31 and 4I. The presence of these apertures and the slot considerably improves the resiliency and freedom of movement of the arms 33, providing a firm grip on the terminal prongs as shown clearly in Fig.

,'7. Here it is seen that the edges of the slot 31 and those of the ends 34. firmly contact with the,

prong I3, and may in fact even slightly cut into the sides of the prong, tracing four lines longitudinally thereof. This insures substantially a perfect electrical contact, and with a self cleaning action.

'Ihe contact structure 23 is adapted to be mounted in the socket receptacle by means of a rivet 45, as shown in Figs.v l to 4, which extends through the aperture 43 in the contact and through the bore 41 in the body of the socket I. The right angled-portion of the contact structure extends up into the chamber 3 of the socket I substantially parallel to the. side walls thereof,

and with the contact arms 33, is in alignment with the socket bore 3. vThe bent. back end 35 ofthe contact structure is adapted to rest against `the inside walls of said lchamber for reinforcing the action. of the said contact stru'cture. It will thus be seen that when the tube prongs are inserted into engagement with the contact structure the latter are sprung slightly toward the side walls. exerting an outward pressure on 'the Drons- I have found that it is pomble because of this construction to even omit the arms 33 and obtain a satisfactory contact between the portion 3| or slot 33 and the terminal prong of the plugin device, although I prefer to obtain more perfect contact by means lof the arms 33 in addition. The reinforced construction resulting from the end 35 of the contact bearing against said walls tends to prevent injury to the contact by vthe insertionof the prongs particularly when the lcontact structure is made of metal having the desired thinness for purpose of flexibility.

To further insure against injury or displacement of the contact I have shown in Fig. 4 al recess 4s extending into the top wan s and inta which an upturned end or projection 5I on the end of the contact slides. An advantage of this vupturned end is that it permits the end of the contact structure more easily to slide along the wall-surface when the prong isv inserted and forces the portion 3| of the terminal toward said wall.

'I'his recess 43 may be in the form of a groove running around the cornerv of the wallfand top portion of the socket but I prefer to limit its length to substantially the width of the end 5I' of the terminal in order to further strengthen said cntact in some cases against the possibility of sidewise displacement. It is therefore obvious that this recess 43 not only tends to prevent sidewise displacement of said contact but likewise prevents inward displacement toward the center of the socket in case the end of an inserted prong should catch on the top edge of arms 33, which are however preferably ared slightly outward and rounded as shown. I have illustrated in Fig. 5; the mounting of substantially 'the same form of contact element,

shown in Figs. 1 to 3, in a depending position from the laminated socket plates 23 and 25. In this construction 'it is not essential for obvious structural reasons that the end '35 of the `terminal rest against a support because of thefact that the character of the combination is differvent from that above. Here a prong of the plug-in Ydevice engages the contact structure, or the upper portion of the arms 33, at a point near the base of support at 23. i

Although in the above gures, I have shown but one step or break between the top surface of the socket receptacle and the socket bore, it

is obvious that one or more steps or breaks may be provided if desirable. It is likewise possible, in Fig. 2, for example, to omit all or certain central portions of the top wall 5 of the socket in case it is desirable to reduce to a minimum the socket material between the prongs of a vacuum tube. Such a structure is shown in Fig. 8. Here, in effect, the receptacle consists of a ring of insulation material 52 mounted on a metal chassis 53 of a radio set by means of a plurality of rivets 55, and the boss I4 on the top of the socket reduces the tendency to breakage. 'Ihe latter improves the insulation by spacingthe top portion 51 away from the metal chassis. 'Ihe fingers 33 may be subdivided as shown,v if

` desired.

bores, particularly in the absence of the guiding means such as the groove ll,taci1itates insertion of the prongs into their sockets.

While I illustrated certain embodiments of my be straight as shown; 'I'he counterbore may also be positioned in any desired relation with respect to the main socket bore.

What I claim as my invention is:

l. An electricalsockct receptacleY for a plug-in device having terminal prong comprising a ring of electrical insulation material, electrical contact structure for said prongs, each structure supported by one end of said ring and extending along the inside wall of said ring toward the other end thereof, and means on the end of said contact structure adjacent said other end of said ring for strengthening said contact structure and for supporting said structure from movement toward said wall during the insertion of the prongs, and characterized in that each contact structure is slotted longitudinally along an intermediate portion and is provided with a pair of contact arms extending therefrom for embracing the inserted prongs.

2. Electrical contact structure `for avacuum l tube receptacle,v comprising a metallic strip. said strip having a base portion for anchorage to said receptacle and a contact Aportion for making connection with one of the prongs of a vacu' -um tube, said contact portion having a longitudinal slot along one side of the said' prong and having fingers extending from said contact portion on either side of said slot for embracing an inserted prong.

3. An electrical receptacle for a'plug-in device having terminal plugs comprising a support of linsulation materialhaving openings in it for the passage of plugs and a pluralityof contact devices secured to the support and each comprising a plate parallel y,to the bottom of the support and an end slitted throughout a large portion of its length and almost to its extremity and carrying contact members folded toward each other from the outer sides of the end portion along the slit, the contact members diil'ering in y contour from the contour of the plugs and adapted to engage the plugs through a part only of their circumferenc 4. As an article of manufacture for operative association with a receptacle base for vacuum tubes, a metallic contact member comprising a contact part and an angularly divergent anchoring portion, the contact part comprising a backing portion and side arms bent toward each other and forming with the backing portion a channel adapted to `receive and resiliently grip a vacuum tube prong, the backing portion being of a sectional prole diiierent from the periphery of such prong, and the arn-isvbeing-joined thereto by junction elements extending the full length axially of the arms so as to impart symmetrical resilience to the contact part, said arms each having a sectional prole dlierent from the periphery of the prong' so as to engage same to tour of such prong inserted axially of the establish lines of contact in circumi'erentialiy spaced relation on the prong and to resiliently urge the prong and backing portion into engagement to establish a third line contact longitudinally of the prong in circumferentially spaced relation to the rst mentioned lines of contact.

5. As an article oi' manufacture for operative association with a receptacle basefor vacuum tubes, a metallic contact member comprising a thereof in position to engage an inserted prong i to establish two lines of the prong substantially cumferentially spaced said arms being bent contact longitudinally of relation on `said prong, outwardly between the rev, and such prong, the arms adapted and arranged to resiliently urge a prong and the backing portion into engagement to establish a third line of contact longitudinally of the prong in circumliiil'rentially spaced relation to the ilrstlmentioned es. Y

ingportion by substantially identical oppositely disposed connections so that the resilience of the channel is symmetrical to the backing portion, the arms being arranged to resiliently engage sides of a prong to establish two lines of contact longitudinally thereof in circumferentially spaced relation and to resiliently engage the prong with the backing portion, and said backing portion having a proiile initially different from the conso as to establish a third circumferentially spaced line of contact longitudinally of the prong between the, prong and said backing portion, and a supplemental slot extending longitudinally of the backing portion through at least one end of said channel to enhance the resilience of said en 7. An electrical socket receptacle for a vacuum tube having a terminal prong which comprises a receptacle base having an aperture for the reception of such prong, comprising an anchoring part secured to the base and an angularly divergent contact part ln substantial alignment axially of the aperture, the

contact part comprising a backing portion subl to the periphery of such prong and integral side ingers bent toward each other and forming with the backing portion a channel to receive and resiliently grip such prong aperture, the arms being attached to the backing portion by connecting elements which are symmetrical thereof so as to secure resilience which is symmetrical axially of the channel, the. arms each having a proile diiat said free ends in cir-.

a metallic contact memberv ferent from the periphery of the prong so as to engage the prong and establish a line of contact longitudinally of the' prong in circumierentially spaced relation, and simultaneously to establisha third line ol contact between the prong and the backing portion in circumferentially spaced re- A lation to the ilrst mentioned lines.

8; An electrical socket receptacle for a plug-in device having substantially cylindrical terminal prongs, comprising an insulating support having a plurality of prong apertures, a plurality of exible metallic contact elements mounted on the support in substantial alignment with appropriate apertures, each element comprising a back contacting portion and integral side extensions of the back portion, said back portion being substantially parallel to the axis oi' said aperture and to the axial path of movement of an inserted prong and merging into anangularly divergent mounting portion, said side extensions having free edges substantially parallel to such axial path when a prong is inserted in the element and being bent so as to dispose their spaced freev edges on and in contactv with the opposite side of a prong from the back contacting portion when a prongis inserted through the appropriate'aperturel and between the back portion and the free ends of said extensions, and said side extension so bent between the respective free edges and the back portion as to secure non-contacting clearance laterally of and with reference to such prong.

9. As an article oi' manufacture for operative association with'a receptacle base for vacuum tubes, a metallic contest member comprising a contact part and an angularly divergent anchoring portion, the contact part comprising a back contacting portion `and integral side extensions of the back portion bent toward each other and forming with the backing portion a channel adapted to'receive and `resiliently grip a vacuum tube prong. said side extensions having free edges substantially parallel to the axis of the channel when such a prong is inserted axially therein and being so bent as to dispose their spaced i'ree'edges on and 'in contact with the opposite side of such prong from the back conv tacting portion when ysuch prong is inserted axially in the channel between the back portionand the free ends oi said extensions, and said side extensions so bent between the respective free edges and the back portion as to secure non-contacting clearance laterally oi and with reference to such prong, each-extension Aancl the backing forming with the backing portion an open-ended channel adapted 'to receive and resiliently grip a vacuum tube prong, one open end of the channel being formed by the termination of the side arms on the opposite side of the curved neck from the mounting portion, the backing portion being of a sectional prole different fromythe periphery of such prong, and the arms being vjoined thereto by junction elements extending the full length axially of the arms so as to impart symmetrical resilience to the contact part, said arms each having a sectional proie different from the periphery of the prong so as to engage same to establish lines of contact in circumferentially spaced relation on the prong and to re'- siliently urge the'pr'ong and backing portion into engagement to establish a third line contact 1ongitudinally or thev prong in circumferentially spaced relation to the rst mentioned lines of contact.

ARTHUR M. DRAVING.

l portion being arranged to secure a line contact 

